Improved process for purifying- pahaffine



C. CHAUCEY PARSONS, OF NEW YORK, N. Y.

Letters Patent No. 93,739, dated August 1T, 186i).

IMPROVED PROCESS FOR PURIFYING PARAFEINE.

The Schedule referred to in these Letters Patent and making part of the same.

To whom it may concern.-

Be it known that I, C. CnAUNonY Iausons, of N ew York, county of New York, and State of New York, have invented a certain new and improved Process for Purifying Iaraiiine; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying diagram.

The old process usually employed for purifying pall'- aine consists in repcatedlymelting the parattne with naphtha, cooling and submitting to hydraulic pressure; but by this process-there is a heavy loss, and a great deal of labor required, besides the expense occasioned by the wear and tear of machinery.

yThe object I have in View is to avoid the defects of the old process, and to this end the essential features of my invention may be stated to consist as follows:

First, melting the paratiine with naphtha, and cooling it while continually agitated. By this means the paratline forms small, sealy crystals, which are easily purified.

Second, washing the paraiiine by passing cold naphtha up through it, stirring it at the same time, so as to expose all the parafline to the naphtha, and doing this at such a speed that the paraiiine remains in the lower part of the vessel in which this operation takes place.

Third, sepa-rating parafne of a lower melting-point from that of a higher melting-point, by Varying the temperature of the naphtha with which it is treated, as described.

In carrying out my process, I make use of an apparatus which will be readily understood from the following description of the diagram accompanying the specification.

Description.

A is a tank lined with lead, with a steam-coil, A', and a draw-oit cock, A.

B is a pump, for transferring thc contents of the tank A to the agitator C, through the pipe B.

C is a metallic tank, whose height should be about twice its` diameter. It is furnished with arms, which reach nearly to its cent-re.

D is an upright shaft, rotating in the centre oi' C, and furnished with horizontal arms, so placed that when rotated they will pass between those placed upon the inside of the tank C. I

E is a tank, about two feetwider and one foot deeper than the tank C, and the latter is placed in the centre of this tank E, in 4such manner that its-top shall be aboutV four inches above the top of the tank E'.

F is a tank ofthe saine dept-h as C, and one-half its diameter. It should be placed about three feet higher than C.

F' is an overflow-pipe, from theI topof F to the -bottom of G, where it is'marle into two or more coils F F, and perforated with small holes in its lower side. The end of this pipe whirh communicates with F is bont down six inches, forming a trap to prevent air from entering it.

G is a small supply-tank, placed above F.

H isa pipo, extending from the bot-toni ofthe tank G to the bottom of the iank F, where it is made into several coils, with' a great numbcr of very small holes on its upper side.

J is a ball-valve, so regulated that the liquid in F shall always be'over the end of the pipo Il".

I is a belt oi' wire gauze, extending horizontally around the inside of the ank (l, at its top. 4lt is inches wide, and there a space or channel of one inch between it and thc tank (l. lt is to be covered with very coarse felt or flannel.

Kis an overflow-rupe, attached two inches from the top of C, inside of the gauze I. rIhis pipe has two branches at its lower end, and by means of the cocks L If, it communicates with both tanks A and M.

M is a tight tank or still, with a draw-ofi' cock, M, a steam-coil, fullvof holes, M", and gooseueck and condensing-worm N. The pipe Ii enters its bottoni. O is a still, with aperforatod steam-coil, O', two draw-cocks S S', one two inc-hes above the other, and

. a gooseneok and comleusing-worm, R. This commuthe vessel C. I treat the paraffine wit-l1 acidl and alkali, if necessary. Having treated it, I draw oii. the impurities through-the cook A".

I then introduce-ono hundred and ifty per cent. of

vthe weight of para-Eine, of naphtha, which should be about 7 00 Baume. I mix this with the paraine at the lowest temperaturent; `which it will dissolve it. I let it stand until all the dirt and other extraneous matters have settled to the bottom, and then pump it into the tank C.

Thetank E, around C, should he previously filled with broken ice and salt.

The agitator is .now turned at anioderatespeed, and by constantly bringing fresh portions of the melted paratiine and naphtha in contact with the outer surlface of the. tank, the contents are rapidly cooled.

The agitator must not be allowed to stop now, the paralflne will become very thick, andsets rapidly. The tankI is filled, to the height indicated by the dotted lines, with finely-broken ice and salt, and water is poured in until it rises within four inches of the end of the pipe F. The tank G is kept liilled with pure naphtha of 70 Baume.

When the temperature of the contents ot the tank Gis nearly 320 Fahrenheit, the cock F is slightly opened. The valve J opens, and the naphtha goes from G to the bottom of F, and then coming through the holes in the coils H', rises through the ice and freezing water in F, is at' once reduced to a temperature of about 320 Fahrenheit, and then overflows into the tank C, through the pipe The napht-ha is admitted, and the agitator is turned as fast as it can be without causing the paraiine to rise u'p above the stirrers and arms.

When worked properly, the paraine should never rise wit-hin a foot of the gauze belt I. At the. temperatnrc' of 320 Fahrenheit, the naphtha will wash out all the oil from the paratlne, and dissolve litt-le, if any, of the paraiilue. A little veryT fine parafiine will occasionally rise, and will be retained by the flannel over the. gauze belt I.

When the naphtha runs nearly colorless, the co'ek L is closed, and L is opened, and enough naptha is run into A for the next charge.

The operation is completed when the naphtha flows through the pipe Kas free from smell and color as when it entered the bottom of C.

\Vhen this takes place, the pipe F is closed, and the agitator is revolved very slowly. After the paraftine has settled to the bottoni of C,`the ooclsis opened and the mixed paraiiinc and naphthadrawn through the pipe I) into the still C, where the naphtha is distlledoti'by' steam, or otherwise.

The condensed water is drawn on" by the cock S', and the melted paraiiine is drawn oli' by the cock S, and formed into moulds.

Steam is also introduced, through the perforations M", into the still BI, until the naphtha is entirely removed, when the heavy oils, &c., are drawn oti through the noch M.

It is essential to prevent the air from entering with' the naphtha through the pipe F', as, by its bubbling np through the contents of the tank O,a considerable quantity of paraiine is brought to the top of the naphtha, which will clog the r'lannel on the wire gauze I, and the tank C may thus be caused to overiiow.

The naphtha distilled oi from the stills 0 and M,

after condensation, can be used again, and so on, in-

definitely.

.lhe object oi using naphtha as light as 700 Baume. is to saverfnel in the' distillation. As the temperature of the vnaphtha introduced through the pipe F rises above 32 Fahrenheit, it will dissolve the paraiflne .of a low melting-point, and the paraine left behind in the tank (l will have a very high melting-point. The temperature oi' the naphtha should nevel' rise above 430 Fahrenheit, or it will dissolve too much parane. lVhen thenaphtha is wanted above 320Fahrenheit, it should hc passed through a pipe immersed in ice, and not as shown in the drawing.

.By this process it is thus possible to either retain all the paraihne, 'so that it will have an average melting point, or to sepalate it, as may be desired, into two or more paraiiines, having varying melting-points: Very often it is desirable to have as high a meltingi point as can be obtained. v

While describing, for the purpose of more fully illustrating my invention, a specific form of apparatus, it will be understood that the arrangement of the same can be greatly varied, and I contemplate theemploynient of any apparatus suitable to carry out the process.

Y Having now described my invention, and the man ner in which the same is or may be carried into eiiect lVhat I claim, and desire to secure by Letters Patent, is-

1 Melting the paraiiine with naphtha, and cooling the saine while continually agitating it, substantially .as and for the purposes described.

2. Washing the paraine by passing coldV naphtha up through it, stirring or agitating the mixture at the same time, so as to expose, as nearly as possible, all the pax-affine to the naphtha, substantially as herein set forth.

3. Separating paraine of a lower melting-point from that of a higher melting-point, by varying the temperature of' the naphtha with which the palane is treated, substantially as set forth.

4. The process for purifying parailine, substantially as herein described.

In testimony whereof, I have signed my name to this speciiication, before two subsciibing witnesses.

` "Witnesses: C. CHAUNCEY PARSONS.

A. POLLOK, WM. J. PARSONS. 

